Biomarker detection from breath samples
Inventors
Lynn, Michael Scott • Heanue, Joseph A. • Anekal, Samartha G. • LIMTAO, Kevin M. • Dunk, Kevin Bradford • Schuster, Jeffrey A. • Stoll, Jeffrey A.
Assignees
Triple Ring Technologies Inc • Hound Labs Inc
Publication Number
US-11977086-B2
Publication Date
2024-05-07
Expiration Date
2040-03-18
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
Methods, systems and techniques for the accurate measurement breath-borne biomarkers are disclosed. Such methods, systems and techniques may be used for the purposes of detection and/or measurement in breath samples of biomarkers.
Core Innovation
The invention provides methods, systems, and devices for accurately measuring breath-borne biomarkers, specifically focusing on tetrahydrocannabinol (THC) detection from breath samples. The approach involves obtaining a breath sample from a subject, excluding droplets larger than an upper range of a desired size range, then capturing aerosol droplets within this range on a surface, eluting these into a small fluid volume, and analyzing the resulting reaction to determine the amount of THC present. The measured amount is compared to a threshold correlated with recent THC use, and the results are visibly or audibly indicated on an associated device.
The patent addresses the challenge of detecting extremely small quantities of THC in breath, where conventional approaches for detecting alcohol are not effective due to the vastly lower concentration of THC. Accurate measurement of THC in breath is critical because breath-based THC detection correlates more directly with impairment than blood or urine testing, which may yield false positives unrelated to recent use. The disclosed solution enables reliable distinction between recent use and non-impaired residual presence.
This innovation includes immunoassay-based detection (such as surface-based antibody-down, antigen-down, noncompetitive, heterogeneous and homogeneous competitive immunoassays), tailored sampling devices (including microfluidic cartridges with optimally configured reaction channels), and a workflow that supports collection, analysis, and reporting at the point of care, such as roadside testing. The approach is adaptable for simultaneous detection of additional analytes or biomarkers in breath, supporting broader applications in medical diagnostics.
Claims Coverage
The independent claim of the patent presents several inventive features that collectively enable selective capture and quantification of THC contained in aerosolized breath droplets with high sensitivity and specificity.
Selective aerosol droplet collection and exclusion of larger droplets
The claimed method requires obtaining a breath sample from a subject, actively excluding droplets larger than an upper size limit (e.g., less than about 5 μm in diameter), and then, after such exclusion, collecting aerosol droplets within the desired size range on a surface. This selective process ensures capture of breath fractions most indicative of recent THC use, overcoming issues with saliva or oral contaminants.
Elution of collected aerosol droplets into a small fluid volume
After collecting the relevant aerosol droplets, the method includes eluting these droplets from the surface into a defined fluid volume. This approach allows for the concentration of analytes into a measurable sample conducive to sensitive downstream analysis.
Introduction of eluted sample into a reaction channel in a test cartridge with defined geometry
A portion of the eluted fluid is introduced into a reaction channel located in a test cartridge, where the channel may have a hydraulic diameter of less than 0.8 mm and a length of at least 40 mm (for example, about 0.7 mm diameter and 57 mm length), facilitating highly efficient mass transfer and detection in microfluidic settings.
Analysis using immunoassay methods within the cartridge
The method includes analyzing the reaction of the sample within the test cartridge, specifically employing immunoassays (e.g., surface-based antibody-down, antigen-down, noncompetitive, heterogeneous/homogeneous competitive immunoassays) to determine the amount of THC in the captured aerosol droplets with high sensitivity.
Threshold-based comparison and explicit result indication
The determined amount of THC is compared to a predetermined breath threshold—such as less than 10 pg/L, typically between 2 to 5 pg/L or even about 2.4 pg/L or 1-2 pg/L—where this threshold is correlated with an average amount of THC between 2 and 3 hours after use. The result (whether the amount exceeds the threshold) is indicated on a device display via a visible, audible, or display-based signal.
Integration of evidence handling for regulatory or forensic standards
The method allows for a second portion of the eluted sample fluid to be introduced into an evidence channel on the test cartridge, supporting evidentiary preservation consistent with regulatory or legal requirements.
The claim coverage defines a method and system that together provide a robust, highly sensitive, and threshold-correlated approach for point-of-care detection of THC in breath. The inventive features collectively ensure specificity for aerosolized biomarkers of interest, enable highly efficient capture and measurement, and support evidentiary standards.
Stated Advantages
Enhanced sensitivity in detecting picogram-level concentrations of THC and other biomarkers in breath samples.
Ability to distinguish between recent THC use associated with impairment and non-recent use, addressing issues of false positives.
Non-invasive, convenient, and rapid point-of-care or roadside testing, supporting immediate analysis and result reporting.
Device scalability and adaptability to detect a wide range of breath-borne biomarkers beyond THC, including indicators of disease states.
Reliability through the exclusion of confounding large droplets and integration of controlled sample handling, improving analytical accuracy.
Meets evidentiary and legal standards required for law enforcement or forensic applications by preserving an evidence sample.
Supports multiplexing and customization for detection of multiple analytes or concurrent alcohol and THC testing from a single sample.
Documented Applications
Roadside detection and determination of recent THC use correlating to impairment during sobriety testing.
Simultaneous detection of both THC and ethanol (alcohol) from a single breath sample for combined impairment assessment.
Detection and evaluation of other airborne or breath-borne substances, including controlled substances.
Diagnosis and monitoring of various disease states through measurement of breath-borne indicators (e.g., stomach cancer, lung cancer, heart failure, kidney failure, diabetes).
Noninvasive point-of-care testing for a range of physiological conditions using portable, including handheld, devices and systems.
Medical diagnostics via detection of specific biomarkers associated with physiological conditions indicated in the provided biomarker tables.
Interested in licensing this patent?